The idea of car-free streets might seem pointless to some, but if selected thoughtfully they are just the kind of peaceful havens that are in too-short supply in Chicago, a civic group says.

That group, which for years has advocated pedestrian- and bicycle-friendly Chicago streets, is releasing a proposal Wednesday for 20 car-free areas and public plazas across the city.

The Active Transportation Alliance's objective is to make downtown and the neighborhoods more attractive places to live and shop, and to help residents get around easily and safely by promoting more bicycling and walking while also reducing traffic accidents, officials at the alliance said.